Scooters and scooter-like manually-powered vehicles are well known within the art for efficient means for transportation. Most scooters are designed and manufactured primarily for recreational use by children, while some scooters are designed for use by adults. Scooters are propelled by the rider using a single stride with one leg, while the other leg and foot maintain contact with the rider platform.
Many scooters of the prior art employ small wheels at the front and/or rear ends of the scooters, such as the designs disclosed in U.S. design Pat. Nos. 300,756; 295,989; and 392,001. Scooters with small wheels are not particularly well suited for use by taller and/or heavier operators, such as adults of 5 to 6 feet in height and up to 250 pounds in weight. The smaller wheels are difficult to keep rolling at a steady speed over uneven surfaces. Further, the frames of many scooters are not designed to support the stresses incurred during use by heavier operators and during higher speed operation.
Typical scooters, like bicycles, are not convenient to store, and cannot be carried indoors for storage easily due to the large frame and handle bar dimensions necessary. The scooter disclosed in U.S. Pat. No. 5,183,129 to Powell, collapses, but the overall design requires significant mechanical complexity and weight, making it unsuitable for high speed use and long-term carrying.
The scooter disclosed in U.S. Pat. No. 5,470,089, to Whitson, et al, is suitable for adult use and discloses larger wheels. The Whitson scooter uses wheels of 2:1 to 3:1 ratio of wheel diameter to the length of the scooter frame. The Whitson scooter also uses a front wheel fork which is tilted at a 30 degree incline from vertical, which allows the scooter frame down rod to descend from the head tube at a nearly vertical angle, thus forming a nearly right angle with the rider platform.
However, the Whitson scooter is not suitable for taller operators and higher speed operation. As the scooter is operated at higher speeds, the rider's propulsion leg will swing a greater horizontal distance, reaching further forward at the beginning of the stride, and continuing further backward towards the end of the stride. Taller riders have longer legs, thus increasing the stride length. The Whitson scooter may pose a hazard to such operation when the front wheel and yoke are turned towards the propulsion leg, as the rider's foot and/or leg may come in contact with the front wheel and front wheel spokes. This poses a potential injury hazard to both the rider and nearby persons
Further, the Whitson scooter's 30 degree front fork causes the front wheel to tilt significantly from a straight vertical orientation during turns, which also poses a potential for the rider to lose balance and wreck the scooter.
Therefore, there exists a need in the art for a scooter which is properly constructed to withstand the stresses and weight for a full-size adult operator propelling the unit at a relatively high speed. There also exists a need in the art for a high-performance steering system design which maintains the front steering wheel in a nearly vertical position during high speed turns, to increase stability and maneuverability. Further, there exists a need in the art for a scooter which presents no overall protrusions, including a turned wheel, which may come in contact with the rider's legs during normal operation, in order to enhance safety of operation. Finally, there exists a need in the art for an enhanced scooter which can be collapsed, and whose design is simple and light weight to lend itself to low-cost manufacturing and long-term carrying in the collapsed position.